Blade sharpening devices commonly used to sharpen knives, particularly kitchen cutlery, typically employ one or more rotably mounted grinding wheels commonly having a cylindrical grinding surface and driven by a motor, typically an electric motor. The grinding wheels employed by such devices typically comprise a blade support and a grinding wheel. Sharpening is accomplished by positioning the blade adjacent a grinding wheel for grinding, the blade being supported on the blade support with the cutting edge in contact with the wheel. Typically current methods fail to produce a sharp edge on kitchen cutlery for the reason that the edge of the blade is permitted to contact the surface of the blade support as well as the grinding stone thereby creating a burr on the cutting edge and leaving the knife blade dull.
In a related field of sharpening where a very sharp edge is sought, that which is burr-free, i.e., razor blades, the standard method of sharpening is to use a plurality, typically two, of opposed grinding wheels, each movably mounted with a gearing mechanism on a parallel axis used to increase the angle of grinding, to produce successive facet angles on the blade, the outermost facet angle being the edge or the tip of the blade. The facet angle which is the included angle contained within the tangents to the two wheel diameters at the point where the tip is formed. Successively grinding operations are performed on the edge or are done at a slightly higher (larger) angle by decreasing the distance between the axis of each wheel and with using finer grit wheels. A control mechanism is used to provide that successive sharpening operations grind less and less material which, with the finer grit produces a smaller radius tip and leaves the tip substantially burr-free.
While this method does produce a very sharp edge, it is expensive, time consuming and requires gearing apparatus to drive the opposing grinding wheels such that the wheels both approach the edge being ground simultaneously. Also the method requires a mechanism to increase the facet angle produced typically by moving the axis of the grinding wheels outwardly. It is therefore desirable to provide a new and improved, economical and simplified cutlery sharpening apparatus and method wherein the sharpening apparatus includes a unitary grinding wheel [mounted in fixed relationship] driven by a motor [and] with a blade guide and produces a substantially burr-free cutting edge.